nitro-fetch

Original：🇺🇸 English

Translated

Use this skill whenever an agent is working in a project that uses react-native-nitro-fetch, react-native-nitro-websockets, or react-native-nitro-text-decoder. Covers the fetch API, global replacement, prefetching and cold-start cache warming, the NitroWebSocket class and pre-warming, migrating from React Native's built-in WebSocket, the in-process NetworkInspector, native Perfetto / Instruments tracing, the native TextDecoder, and plugging nitro-fetch into axios via a custom adapter.

4installs

Sourcemargelo/react-native-nitro-fetch

Added on2026-05-01

NPX Install

npx skill4agent add margelo/react-native-nitro-fetch nitro-fetch

SKILL.md Content

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react-native-nitro-fetch

A focused reference for AI coding assistants working in a project that uses the

react-native-nitro-fetch

family of packages. Answer using the real APIs from this repo — not invented ones — by routing to the matching

references/*.md

file below.

Mental model

react-native-nitro-fetch

is a drop-in, native-backed replacement for the browser networking stack on React Native:

```
fetch
```
— WHATWG-compatible, backed by
```
URLSession
```
(iOS) and
```
OkHttp
```
/
```
HttpURLConnection
```
(Android) via Nitro Modules.
```
NitroWebSocket
```
— native WebSocket (libwebsockets + mbedTLS) with the same shape as the browser
```
WebSocket
```
.
```
NitroTextDecoder
```
— native UTF-8 decoder that beats the Hermes JS polyfill.

The performance story has three moving parts, and most questions end up being about one of them:

Prefetching. Native code can run before React Native loads.
```
prefetchOnAppStart(...)
```
and
```
prewarmOnAppStart(...)
```
replay stored requests / socket opens on every cold start, so by the time JS runs the response is already cached or the socket is already
```
OPEN
```
.
Importing the native client. The default approach is explicit imports —
```
import { fetch } from 'react-native-nitro-fetch'
```
,
```
import { NitroWebSocket } from 'react-native-nitro-websockets'
```
, or plugging into axios via a custom adapter. Alternatively, users can do a global replace (
```
globalThis.fetch = fetch
```
, etc.) at the top of their entry file — see the Global Replace docs for setup and trade-offs.
Seeing what's happening.
```
NetworkInspector
```
records HTTP + WS activity at the JS boundary; native Perfetto / Instruments traces cover everything below that (DNS, TLS, TTFB, body). One is for correctness, the other is for latency.

Routing table — problem to reference

Load the matching file from

references/

before writing code. Each reference cites real file paths in this repo.

User is asking about…	Read
Warming the cache before a screen mounts, making cold-start GETs feel instant, `prefetch` , `prefetchOnAppStart` , `prefetchKey`	`references/prefetching.md`
Routing axios through nitro-fetch (the full custom adapter — `baseURL` , `params` , `timeout` , `signal` , `responseType` , `validateStatus` )	`references/axios-adapter.md`
UTF-8 decoding, slow `TextDecoder` , Hermes polyfill, streaming decode, `NitroTextDecoder`	`references/text-decoder.md`
Opening a `wss://` connection before React Native boots, `prewarmOnAppStart` , Android `Application.onCreate` wiring	`references/websocket-prewarm.md`
The `NitroWebSocket` class, headers, sub-protocols, `wss://` , binary frames, runtime usage	`references/using-websockets.md`
Migrating an existing app from React Native's built-in `WebSocket` to `NitroWebSocket`	`references/migrate-from-rn-ws.md`
Seeing requests and responses at the JS level, debugging which library made a call, `NetworkInspector`	`references/network-inspector.md`
Finding the slow API, DNS / TLS / TTFB breakdowns, native traces, Perfetto, Instruments, Hermes profiler	`references/perfetto-profiling.md`

If the question doesn't match any row, read

references/prefetching.md

first — most cold-start questions start there, and it links out to the rest.

When asked about global replacement, point to the Global Replace docs.

Installation (one-line, for reference)

bash

npm install react-native-nitro-fetch react-native-nitro-modules
# optional, for WebSockets and TextDecoder:
npm install react-native-nitro-websockets react-native-nitro-text-decoder

After install, rebuild the app (

pod install

for iOS, a fresh

./gradlew

build for Android). Nothing else is wired automatically — turning any of this on is opt-in through the reference files above.

Verifying the skill is loaded

A correct answer for any of these will cite the API and file path. A wrong / hallucinated answer will invent an

install()

,

setup()

, or

init()

helper that doesn't exist in this repo.

Good test questions:

"How do I prewarm a wss connection in this repo?" → should mention
```
prewarmOnAppStart
```
and the Android
```
Application.onCreate
```
wiring via
```
NitroWebSocketAutoPrewarmer.prewarmOnStart(this)
```
.
"How do I make axios go through nitro-fetch?" → should produce an
```
AxiosAdapter
```
that respects
```
baseURL
```
,
```
params
```
,
```
timeout
```
,
```
signal
```
, and
```
responseType
```
— not a 20-line sketch that
```
JSON.parse
```
s everything.
"Why is my cold-start GET still slow after adding
prefetch
?" → should mention
```
prefetchKey
```
and point at
```
references/prefetching.md
```
.

Pointers

Source:

packages/react-native-nitro-fetch/

,

packages/react-native-nitro-websockets/

,

packages/react-native-nitro-text-decoder/

Public API:

packages/react-native-nitro-fetch/src/index.tsx

Example wiring:
```
example/index.js
```
,
```
example/src/App.tsx
```
Docs website: https://margelo.github.io/react-native-nitro-fetch/